Android原始XML的读写操作

Android原始XML的读写操作

代码如下：

package com.example.xml2;

import java.io.File;
import java.io.FileInputStream;

import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;
import com.xh.tx.bean.Person;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.util.Xml;

public class MainActivity extends Activity {

	private static final String TAG = "MainActivity";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		List<Person> list = new ArrayList<Person>();
		Person p = null;
		
		for(int i=0; i <10; i++ )
		{
			p = new Person(i,"zs" + i,"[email protected]","西安南路" + i+ "号");
			list.add(p);
		}
		
		writePerson(list);
		
		readPerson();
	}
	/**
	 * 有一个List<Person> list ;
	 * 把list里面的所有对象序列化到sdcard里面形成一个xml文件
	 */
	
	public void writePerson(List<Person> list)
	{
		if(null == list)
		{
			return;
		}
		
		XmlSerializer serializer = Xml.newSerializer();
		File path = new File(Environment.getExternalStorageDirectory(),"list_person.xml");
		try {
			FileOutputStream out = new FileOutputStream(path);
			
			serializer.setOutput(out, "utf-8");
			
			//开始序列化xml
			serializer.startDocument("utf-8", true);
			
			//根
			serializer.startTag(null, "persons");
			
			for(Person p : list)
			{
				serializer.startTag(null, "person");
				serializer.attribute(null, "id", String.valueOf(p.getId()));
				//推进使用String.valueOf 将其他类型的对象转化为string对象
				
				serializer.startTag(null, "name");
				serializer.text(p.getName()); //<name>allen</name>
				serializer.endTag(null, "name");
				
				serializer.startTag(null, "email");
				serializer.text(p.getEmail()); 
				serializer.endTag(null, "email");
				
				serializer.startTag(null, "address");
				serializer.text(p.getAddress()); 
				serializer.endTag(null, "address");
				
				serializer.endTag(null, "person");
			}
			
			
			serializer.endTag(null, "persons");
			
			serializer.endDocument();
			
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public void readPerson()
	{
		//工具类 我们称这种方式为pull解析（DOM,SAX,DOM4J）
		XmlPullParser parser = Xml.newPullParser();
		
		try {
			FileInputStream in = new FileInputStream(new File(Environment.getExternalStorageDirectory(),"list_person.xml"));
			parser.setInput(in, "utf-8");//设置你要解析那个文件，已什么编码格式把它读入到内存
			
			//下面开始解析xml
			int eventType = parser.getEventType();
			List<Person> list = null;
			Person p = null;
 
			while(eventType != parser.END_DOCUMENT)
			{
				switch (eventType) {
				case XmlPullParser.START_TAG: //访问静态变量的时候用类名来访问，不要用对象去调用
					if("persons".equals(parser.getName()))
					{
						list = new ArrayList<Person>();
					}else if("person".equals(parser.getName())) //当遇到了person节点的时候创建person对象并解析id属性给person对象
					{
						p = new Person();
						int id = Integer.parseInt(parser.getAttributeValue(null, "id"));
						
						p.setId(id);
					}else if("name".equals(parser.getName()))
					{
						String name = parser.nextText(); //一般用nextText 不用getText
						
						p.setName(name);
					}else if("email".equals(parser.getName()))
					{
						String email = parser.nextText(); //一般用nextText 不用getText
						p.setEmail(email);
					}else if("address".equals(parser.getName()))
					{
						String address = parser.nextText(); //一般用nextText 不用getText
						p.setAddress(address);
					}
					break;
					
				case XmlPullParser.END_TAG:
					if("person".equals(parser.getName()))//表示person结束了,将person对象加入到list中
					{
						list.add(p);
						
						p = null; //及时的让我们不用的对象成为垃圾
					}
					break;

				default:
					break;
				}
				
				eventType = parser.next(); //尤其容易忘记
			}
			
			//打印一下解析出来的所有对象
			for(Person person : list)
			{
				Log.d(TAG, person.toString());
			}
			
		} catch (XmlPullParserException e) {
			e.printStackTrace();
		}
		catch (Exception e) {
			e.printStackTrace();
		}
	}
	
}

Person类代码：

package com.xh.tx.bean;

public class Person 
{
	private int id;
	private String name;
	private String email;
	private String address;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	
	public Person() {
		super();
	}
	public Person(int id, String name, String email, String address) {
		super();
		this.id = id;
		this.name = name;
		this.email = email;
		this.address = address;
	}
	@Override
	public String toString() {
		return "Person [id=" + id + ", name=" + name + ", email=" + email
				+ ", address=" + address + "]";
	}
}

还需要在 AndroidManifest.xml 中注册

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>